Troubleshooting when Addons don't show up
Addon which name (or folder name) contains  . (dot) cannot be loaded in Add-ons list. See this bug report.

Take list below for example:



Lens0.3 cannot be seen in Blender's Add-ons tab. And MultiEdit2.5.py cannot be sucessfully enabled even though it can be found in the list.

Solution would be to manually remove dots or replace with other valid characters.